The mass distribution of behind-armor debris generated during the normal penetration of variable cross-section explosive formed projectile on rolled homogeneous armor steel

Abstract

Since the mass distribution of behind-armor debris (BAD) is an important measurement to evaluate the level of destruction caused by BAD, this work proposes a new approach for predicting the mass distribution of BAD generated during the normal penetration of variable cross-section explosive formed projectile (EFP) on rolled homogeneous armor (RHA) steel. Few papers considered the variable cross-section characteristic of EFP, and it is an important influencing factor on number of BAD from target and EFP. In this paper, the variable cross-section characteristic of EFP, the strength of EFP, the axial length of mushroom of EFP, the nose shape of the EFP are all considered, besides, the fit factor of the average strain rate and the fit factor of Mott formula are introduced. The number of BAD from target and EFP as well as the mass distribution of BAD from target and EFP, could both be predicted by modified formula on the base of theoretical analysis and numerical simulation, then it is verified by the experiment. The results indicate that: 1) compared with ignoring the variable cross-section characteristic of EFP, the accuracy of the number of BAD from target and EFP could be improved as the variable cross-section characteristic of EFP is considered; 2) the modified Mott formula can describe the mass distribution of more than 90% BAD from target and EFP.